Machine for abrasive finishing of contoured or profiled surfaces



ARMYTAGE MACHINE FOR ABRASIVE FINISHING 0F CONTOURED 7 OR PROFILEDSURFACES Filed June 20, 1960 July 10, 1962 7 Sheets-Sheet l JulylO, 1962F. w ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING OF CONTOURED OR PROFILED SURFACES 7Sheets-Sheet 2 Filed June 20, 1960 July 10, 1962 F. w. ARMYTAGE3,043,057

MACHINE FOR ABRASIVEI FINISHING OF CONTOURED OR PROFILED SURFACES FiledJune 20, 1960 7 Sheets-Sheet 3 y 0, 1962 F. w ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES I FiledJune 20, 1960 7 Sheets-Sheet 4 y 10, 1962 F. w. ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING OF CONTOURED OR PROFILED SURFACES FiledJune 20, 1960 7 Sheets-Sheet 5 uly 1962 F. w. ARMYTAGE 3,043,057

MACHINE FOR ABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES FiledJune 20, 1960 7 Sheets-Sheet 6 July 10, 1962 F. w ARMYTAGE MACHINE FORABRASIVE FINISHING 0F CONTOURED OR PROFILED SURFACES 7 Sheets-Sheet 7Filed June 20, 1960 it is This invention relates to the honing, lapping,polishing or similar abrasive treatment of contoured or profiledsurfaces. Heretofore this treatment has been manually controlled so faras the guiding of the abrasive tool or medium and its pressure againstthe surface and its speed of travel thereover was concerned, andconsequently the amount of material removed from the workpiece and theuniformity and quality of the surface finish depended largely upon theskill of the operator.

The object of the present invention is to provide a machine capable ofabrasively treating contoured or profiled surfaces without humanguidance once it has been set in operation and capable of producingrapidly and accurately a surface finish having a high degree ofuniformity.

To this end a machine according to the invention includes means formoving the contoured or profiled surface of the workpiece relative tothe abrasive tool or medium, means for traversing said tool or mediumover and in contact with said surface so as to treat the whole of thedesired area thereof, and hydraulic tracer valve mechanism arranged tobe actuated by movement of said tool or medium and thereby to maintainthe latter in contact with said surface with a substantially constantpredetermined pressure. By these means the abrasive tool or mediumitself acts as a stylus or tracer foot and through the tracer valveoperates automatically to follow the contour or profile of the surfacewith a constant pressure.

In order to enable the machine to produce the desired high qualityfinish on workpieces of widely differing shapes, sizes and surfacecontours, means are provided for varying independently the speed atwhich the workpiece is rnoved and the speed at which the abrasive toolor medium is traversed, whereby the relative movement between the tooland the workpiece can be caused to take place. at a speed which ensuresthe necessary high quality surface finish.

The form of movement given to the workpiece and to the .tool may varyaccording to the type of work which the machine is required to do. Oneor both movements might be reciprocatory or rotary, and preferably thecombination of movements is arranged to cause the tool to cover thecontoured or profiled surface in a non-repeating pattern.

I1 treating workpieces on which the surface extends through 360 orsubstantially so it is found convenient to rotate the workpiece and toreciprocate the tool across its surface transversely to the path inwhich the latter rotates.

Provision may also be made for oscillating the workpiece through anysuitable included angle up to 360 in order to provide the surface honingto a contour which it is more convenient to deal with in sections, asfor instance in a glass container mould which is in two or more parts.

It has been found advantageous to oscillate the hone across the twomating parts separately.

The tool and tracer valve are mounted on a carrier which is slidable ina reciprocatory head under control from the tool actuated valve, andthis carrier or the tool itself or both independently is or areadjustable angularly to enable the tool to approach the workpiecesurface at the most advantageous angle.

In order that the invention may be clearly understood 3,643,357 PatentedJuly 10, 1962 and readily carried into efiect the same will now be morefully described with reference to and by the aid of the accompanyingdrawings, which illustrate by way of example one construction of machine(and some modifications thereof) embodying the invention and suitedmainly for treating the interior or exterior of workpieces on which thesurface to be treated extends substantially around 360.

In these drawings: 7

FIGURE 1 is an elevation of the machine from which the tool andworkpiece are omitted.

FIGURE 2 is an end elevation seen in the direction of arrow A in FIGURE1 but showing a tool and workpiece in position;

FIGURE 3 is a plan of FIGURE 1;

FIGURE 4 is a partial horizontal section on the line IV--IV of FIGURE 1;

FIGURE 5 is a view similar to that in FIGURE 1 of the tool holding andtracer deflecting mechanism mounted with the tracer valve upon atracer-controlled tool slide;

FIGURE 6 is an end elevation seen in the direc ion of arrow B in FIGURE5, parts being shown in section;

FIGURE 7 is an underneath plan of the tool holding and tracer deflectingmechanism shown disconnected from the tool slide;

FIGURE 8 is a partial view of modifications showing a reciprocatablework slide for use in place of the rotatable work table and showing athree-station turret which can be used to hold three tools;

FIGURE 9 is a horizontal section on the line IX-IX of FIGURE 8 showinghow the tool could operate on a flat workpiece in that instance;

FIGURES 10 and 11 are detail views of adjustable extensions for the toolholder.

Referring first to FIGURES l to 4, the machine has a frame 1 supportedon wheels 2 and carrying in its lower part 3 an oil reservoir. Anelectric motor 4 drives an oil pump '5 which draws oil from thereservoir and pumps it to an oil motor 6 through pipe connections (notshown). The oil motor 6 drives through a V belt 8 and pulleys 7, 9 theshaft 10 of a circular rotatable magnetic worktable 1 1 whose speed canbe maintained substantially constant during the honing operation.

The worktable can be rotated in either direction continuously.Alternatively, if desired to suit the workpiece to be treated, the worktable can be oscillated under preset control of an oil hydraulicreversing mechanism 12 (see FIGURE 4) whose actuator arm 13 isalternately operated by two dOgs 14 inserted in a reversing disc 15secured on the work table shaft 10.

Above the worktable is a reciprocatory head 16 vertically slidable uponthree pillars 17 by the ram rod 18 of and oil hydraulic ram working in acylinder 19 mounted with the pillars on the machine frame 1. The ram canbe set to reciprocate the head 16 over a predetermined length of strokeat a predetermined substantially constant speed during the honingoperation, the oil being supplied to the cylinder 19 by the pump 5. Areversing rod 20 supported by centralising springs 21 in brackets 22, 23secured respectively to the top of the pillars 17 and to the frame 1carries two stops 24 having projections 24X engageable by a dog 25 onthe head 16. The stops can be roughly adjusted along the rod quickly bya sliding movement or slowly to give accurate adjustment by a micrometerscrew. The rod 20 has two pins 26 arranged to operate alternately theactuator bar 27X of an oil hydraulic reversing mechanism 27 mounted inthe frame 1. This mechanism 27 and the reversing mechanism 12 can be ofany suitable construction, but are preferably constructed and arrangedas described and shown in my pending British patent application No.30,457/58.

variations in the shape of Referring more particularly to FIGURES to 7,the

head 16 carries a saddle 28 having an annular T-sectioned slot 29 inwhich engage the heads 30 of studs secured in a tracer-controlled toolslide 31. By this means the tool slide 31 can be adjusted angularlyrelative to the 'head in a vertical plane through 360, although aswivelling movement of about 180 would be suficient to meet mosttreated.

The saddle 32 of the tool slide 31 is reciprocated by a ram working inan oil hydraulic cylinder 33 in known fashion under control from atracer valve 34 of a suitable construction similar to those used forautomatic hydraulic copying tracers of machine tools, and preferably avalve embodying the constructional features disclosed in my BritishPatent No. 692,642. The tracer valve is conplied by pipe connections(not shown) to the cylinder 33 and to a source of oil under pressure(independent of the oil pump 5) as will be understood by those skilledin the art. 1 a r The tracer valve is secured by its stem 35 in abracket 36 which is secured to the saddle 32 by a stud 37 whose axis isparallel to the swivelling axis of the saddle itself. On slackening thisstud the bracket can be adjusted angularly relative to the saddle in avertical plane through The bracket 36 carries a tool-holding andtracer-deflecting mechanism. This consists of a deflector arm 33 pivotedat one end in the bracket by a pivot pin 39 with ball bearings 40 togive maximum freedom fromfriction. The arm near its other end worksbetween two freely rotatable guide rollers 41 which are mounted on thebracket 36 to guide the arm in its vertical movement with the minimum offriction and yet to resist sideways pressure on the arm. Mounted in thebracket 36 is a deflectorspindle 42 whose foot 43 is urged into contactwith the arm 38 by a coil spring 43X surrounding the spindle within a'sleeve 44 which is screwed into the bracket by a knurled head 45 tocompress the spring. By this means a pre-determined constant pressurecan be exerted upon the deflector arm 38, the downward move ment beinglimited by a stop pin 46. The spindle 42 carries a nose piece 47 whichmakes point contact with a stud 48 secured in an arm 49 which isarranged to actuate the spool or equivalent movable member of the tracervalve 34. I u r The deflector. arm 38 has well spaced from its pivotpoint alternative sockets 50, 50a, 50b, to receive the shank of a honingor like tool 51a in the form of a spindle which extends in the oppositedirection to the deflector spindle and which has applied to or securedon its foot, on the side facing towards the deflector arm'pivot and/ oron its end, a stone or'other suitable form of abrasive element. Thesocket 50b is provided in an L-shaped arm 52 pivoted at 53 on the arm-38and adjustable through 90 by a clamping stud 54 working in a segmentalslot 55.

a As indicatedin FIGURE 5, the socket-50 may be used for internal honingof workpieces such as the bottle mould W1 shown and the socket 50a forexternal honing of suit able workpieces. 'Alternatively, as shown inFIGURES and 1 1 by securing the tool in an adaptor 56 or 56X which inturn is secured in the socket 50b, the tool 51b or 510 can be made toapproach the work at the most suitable angle, that shown in FIGURE 10being suitable for treating a hemispherical workpiece W2 whilst thatshown in PIGURE-11-is suitable *for treating the inside of a cup-shapedworkpiece W3. In both these figures the bracket 36 has been angularlyadjusted, either by itself or by the angular adjustment of thetracer-controlled tool slide or by the combined angular adjustment ofboth these members. The combination of these two swivelling movementsenables the tool foot to be broughtto bear on the contoured surface fromthe most advantageous angle in each particular case. a

The operation of the machine is as follows. With the the contouredsurfaces to be workpiece held on the worktable '11, the tool foot setconveniently to the contour face to be honed and the stroke of'the head16 set by the rod 20 to suit the height of such face, the oil pump 5 isstarted, the speeds of the rotary worktable and of the reciprocatoryhead are adjusted by the control knobs 60 and 61 which are capable ofgiving an infinite speed variation over a predetermined range, andhoning commences. The tool foot is held against the workpiece surfacewith a constant pressure which can be predetermined by the setting ofthe spring 43X, and any increase in' this pressure applied by thecontour to the tool foot at any point between w and x (see FIGURES 5, l0and 11) will move the foot away in the direction of arrow y and operate,through the tracing valve, the tool saddle 32 which will move away inthe direction of arrow 1. Similarly any decrease in the pressure of thefoot on the surface causes corresponding opposite movements. Thus ineffect the tool itself is a sensing head which is traversed over thesurface of the workpiece by (in the above example) a combination ofrotary and reciprocatory movements at a predetermined speed, whereby therate of metal removal can be smaller and slower than with other honingor polishing machines, thereby producing a better surface finish withthe minimum amount of material removed in the process.

In order to make more certain the movement of the tool over thecontoured surface'in a non-repeating pattern, control means may beincorporated in the hydraulic circuit to the head-reciprocating ram togive this ram different speeds on its upward and downward strokes.

By using a single oil pump to supply oil to both the oil motor operatingthe table and the ram operating the head, the total volumeof oilsupplied is divided between these two in the correct proportion toensure the maximum footage (i.e. area of contoured surface treated perunit time).

The tool on the deflector arm can swing freely about the arm pivot tofollow the contour on the workpiece but is guided so as to resist thetorque exerted on it by the rotating workpiece. By mounting the toolspindle at apoint cifset from the arm pivot the spindle can yield tolengthwise pressure as well as sideways pressure to operate thedeflector arm regardlessof the direction of movement of thereciprocating head at that moment.

If desired, instead of using the single tool as above described, aturret 62 (see FIGURE 8) may be secured in any one of the sockets 50, a,50b in the deflector arm 38 and adapted to hold (for example) threetools, say a roughing hone, a medium hone and a finishing hone, any oneof which can be turned into working position at choice and locked there.

In a modified form of the construction above described (see FIGURES 8and 9) suited. for treating a flat 1 workpiece W4 onwhich the contoursextend across a substantially plane surface so that it is moreconvenient to reciprocate the workpiece relative to the tool instead ofrotating it, a workholding saddle 63 reciprocated by the ram of ahydraulic cylinder 64 is slidable on a workslide 65 secured upon themachine frame 1 instead of the rotary worktable, the latter beingimmobilised if left in placein the machine. The saddle 63 is mounted soas to be reciprocated in a direction at right angles to that in whichthe tool slide 31 reciprocates or at any other angle best suited to thecontour to be treated in each particular case, and the ram (fed with oilfrom the oil pump 5) could have its length and speed of stroke varied aspreviously, described-with reference to the vertical ram to suit eachjob. Thus a vertical reciproca: tion of the tool 51a and a horizontalreciprocation of the workpiece could bearranged to cover any flat C011?toured area with a non-repetitive pattern, the contoured surface beingmounted in a mainly vertical plane. 'In a further modified arrangement(which will be readily understood without illustration), andwith thecontoured surface held face upwards on the rotatable worktable, thetracer-controlled tool slide would be swung through approximately 90compared with its previously described direction so that the variationsin the depth or height of the contour would be taken care of by thedeflection of the tracing valve through the tool-holding mechanismpressing the tool down onto the contoured surface. In this case anadditional ram-operated slide (or the workslide already referred to) maybe interposed between the swivelling tracer-controlled tool slide andthe vertically reciprocatable head carrying it, whereby the tool can begiven a constant horizontal reciprocatory movement suitable for treating(say) convexed or concaved contours 011 a workpiece mounted flat on therotatable worktable.

I claim:

1. In a machine for the abrasive finishing of contoured surfaces ofworkpieces, the combination of an abrading tool, means for holding aworkpiece, means for moving said workpiece and holder for cuttingmovement relative to saidabrading tool, means for holding said abradingtool and for traversing it over and in contact with the contouredsurface of said workpiece to thereby treat the whole of the desired areathereof, a hydraulic tracer valve mechanism mounted to be traversiblewith said tool, and to cause said tool to follow said contoured surface,a tool-holding and tracer-deflecting mechanism for transmittingdeflections of said tool produced by its contact with said contouredsurface to said tracer valve and means maintaining said tool in contactwith said surface with a substantially constant predetermined pressure.

2. A machine according to claim '1 including means for varyingindependently the speed at which the Workpiece is moved and means forcontrolling the speed at which the abradi-ng tool is traversed, wherebythe relative movement between the tool and the workpiece takes place ata sutficient speed to ensure a high surface finish.

3. A machine according to claim 2, wherein said means for varying thespeed of said workpiece and the means for controlling the speed of thetool are each operatively connected to driving means and a hydraulictransmission therefor operated by oil hydraulic pressure supplied from asingle source, in which the total volume of oil supplied to said sourceis divided between each of said two driving means in predeterminedproportion.

4. A machine according to claim 3 wherein said tool holding and tracerdeflecting mechanism is actuated by upward and sideways movement of saidabrading tool, and in which said abrad'ing tool projects down from saidmechanism.

5. A machine according to claim 4, wherein said tool holder of saidtracer deflecting mechanism pivoted for vertical movement and includesmeans for securing a tool therein to one side of said pivotal point,including means for guiding said holder for free vertical movement toresist movement of said holder in the other direction by the action ofthe moving workpiece on said tool.

6. A machine according to claim 5 wherein said means for exerting apredetermined pressure of said tool against the workpiece is adjustablewithin limits whichavoid restricting the accuracy of the reaction of thetracer valve.

7. A machine according to claim 6 wherein said tool holding and tracerdeflecting mechanism is mounted on a head for vertical reciprocationrelative to said substantially horizontally movable workpiece and isprovided with means for angular adjustment relative to said head in asubstantially vertical plane to enable the tool to be presented to theworkpiece surface at a predetermined angle.

8. A machine according to claim 7 wherein said tool holding and tracerdeflecting mechanism is mounted on a tracer controlled tool slide whichis in turn mounted 1 References Cited in the file of this patent UNITEDSTATES PATENTS 2,354,347 Peets July 25, 1944 2,391,983 Kutzler Jan. 1,1946 2,887,827

Conte et a1 May 26, 1959

